In recent years, the organic light emitting diode display (OLED) as an emerging flat-panel display has received extensive concern. But the traditional OLED device, especially the low work function electrode and the organic functional layer therein, tends to degrade in performance because oxygen and moisture in the surrounding environment enter into the OLED device, this will seriously affect the service life of the OLED. If the OLED device is sealed in a water-free and an oxygen-free condition, the life of the display device can be significantly extended, therefore, an encapsulating technical of the OLED device becomes the key process of improving the life of the OLED display device, and researching and developing an effective encapsulating technical to block water vapor and oxygen becomes an urgent task to be settled.